the timing belt on the A3/B4 is only rated at 60K. however you do not need to replace the water pump or some motor mount bolts on every belt change like the A4 so it is cheaper.
you need this kit (or equivalent parts from a reputable seller... do not use cheapo parts)
http://www.idparts.com/timing-belt-kit-a3-ahub4-1z-p-1045.html
you can even go cheaper by skipping the serp belt, power steering belt and cam seal if they are in good shape... but most ppl just replace them because they are already all up in there. you cannot skip the valve cover gasket, because those all leak... i think its a factory option in order to lube the intake manifold... lol
as for tools, you can buy a good set for 100-150 or rent them from some vendors with a small deposit. buying them is still cheaper than paying the dealer to half-arse it.
if you do it all correct, mechanically speaking, it will start, run and drive just fine until you get it to someone with a VCDS and have them adjust timing to the optimal spot. it can wait a week or longer... no biggie.
heres the write-up on how to:
https://www.tdiclub.com/articles/A3-TimingBelt/ HOWEVER i disagree about turning the engine to TDC with the cam sprocket... i believe it should always be done with the crank bolt instead (12pt 19mm)